reproduce-bug

name	reproduce-bug
description	Step-by-step procedure to reproduce a bug. Use this FIRST before trying to fix anything. Produces a minimal script that demonstrates the failure.

Reproduce Bug

You are reproducing a bug. Follow these steps exactly in order. Do not skip steps or read additional files beyond what each step specifies.

Step 1: Identify the test framework

ls package.json 2>/dev/null && cat package.json | grep -E "vitest|jest|mocha|tap" | head -5
ls *.toml 2>/dev/null | head -3

Note which test runner is available (vitest, jest, etc.).

Step 2: Find existing related tests

find . -name "*.test.*" -o -name "*.spec.*" | grep -i "<keyword from bug description>" | head -10

If you find relevant test files, read them to understand how the codebase tests similar functionality.

Step 3: Write a minimal reproduction script

Create a file called repro.ts (or repro.js / repro.py depending on the project language) that:

1. Imports the minimum necessary from the project
2. Sets up the simplest possible environment (in-memory DB, mock server, etc.)
3. Calls the function/endpoint described in the bug
4. Prints ACTUAL output clearly
5. Prints EXPECTED output clearly
6. Prints PASS or FAIL

Keep it under 50 lines. Use the write tool to create the file.

Step 4: Run the reproduction

npx tsx repro.ts 2>&1

Or the appropriate runner for the language. Report:

• Exit code
• ACTUAL vs EXPECTED output
• Whether the bug is confirmed

Step 5: Report result

State clearly:

• "BUG CONFIRMED: [one-line description of what goes wrong]"
• OR "BUG NOT REPRODUCED: [what happened instead]"

If not reproduced, adjust the repro script (maybe the setup is wrong) and try ONE more time. If still not reproduced after 2 attempts, report that.

Constraints

• Do NOT read source code in this skill. You are only writing and running a reproduction script.
• Do NOT try to fix the bug. Only reproduce it.
• Maximum 8 tool calls for this entire skill.